scholarly journals Extreme pressure forecasting methodology for the hydraulic jump downstream of a low head spillway

RBRH ◽  
2020 ◽  
Vol 25 ◽  
Author(s):  
Roberta Ferrão Hampe ◽  
Renato Steinke Júnior ◽  
Maurício Dai Prá ◽  
Marcelo Giulian Marques ◽  
Eder Daniel Teixeira
Keyword(s):  
Froude Number ◽  
Hydraulic Jump ◽  
Extreme Pressure ◽  
Discharge System ◽  
Flow Discharge ◽  
Economical Design ◽  
Low Froude Number ◽  
Low Head

ABSTRACT Extreme pressures in the hydraulic jump are associated with risk of damage to the flow discharge system of dams by a series of mechanisms. Therefore, understanding and predicting these efforts are crucial for the safe and economical design of discharge systems. Thus, this paper aims to validate an existing pressure forecasting methodology for estimating the extreme pressure in the hydraulic jump with low Froude number (below 4.5). Results have shown that the method may be used for this situation on a preliminary basis. Further studies are recommended to refine the technique and to achieve results that are more precise.

Further Results on Lee Vortices in Low-Froude-Number Flow

1991 ◽  
Vol 48 (19) ◽  
pp. 2204-2211 ◽  
Author(s):  
Richard Rotunno ◽  
Piotr K. Smolarkiewicz
Keyword(s):  
Froude Number ◽  
Low Froude Number ◽  
Number Flow

The Denver Cyclone. Part I: Generation in Low Froude Number Flow

1990 ◽  
Vol 47 (23) ◽  
pp. 2725-2742 ◽  
Author(s):  
N. Andrew Crook ◽  
Terry L. Clark ◽  
Mitchell W. Moncrieff
Keyword(s):  
Froude Number ◽  
Low Froude Number ◽  
Number Flow

Discussion of “Stilling Basin Design for Low Froude Number”

1976 ◽  
Vol 102 (6) ◽  
pp. 797-799
Author(s):  
Heramb D. Sharma ◽  
Dharam V. Varshney
Keyword(s):  
Froude Number ◽  
Stilling Basin ◽  
Low Froude Number

scholarly journals Nose-Angle Bridge Piers as Alternative Countermeasures for Local Scour Reduction

2018 ◽  
Vol 13 (2) ◽  
pp. 110-120 ◽  
Author(s):  
Ibtesam Abudallah Habib ◽  
Wan Hanna Melini Wan Mohtar ◽  
Atef Elsaiad ◽  
Ahmed El-Shafie
Keyword(s):  
Froude Number ◽  
Local Scour ◽  
Bridge Piers ◽  
Scour Depth ◽  
Skew Angle ◽  
Flow Angle ◽  
Sediment Size ◽  
Low Froude Number ◽  
Skew Angles ◽  
Depth Reduction

This study investigates the performance nose-angle piers as countermeasures for local scour reduction around piers. Four nose angles were studied, i.e., 90°, 70°, 60° and 45° and tested in a laboratory. The sediment size was fixed at 0.39 mm whereas the flow angle of attack (or skew angle) was varied at four angles, i.e., skew angles, i.e., 0°, 10°, 20° and 30°. Scour reduction was clear when decreasing nose angles and reached maximum when the nose angle is 45°. Increasing the flow velocity and skew angle was subsequently increasing the scour profile, both in vertical and transversal directions. However, the efficiency of nose angle piers was only high at low Froude number less than 0.40 where higher Froude number gives minimal changes in the maximum scour depth reduction. At a higher skew angle, although showed promising maximum scour depth reduction, the increasing pier projected width resulted in the increase of transversal lengths.

A Contribution to Study on the Lift of Ventilated Supercavitating Vehicle With Low Froude Number

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Yu Kaiping ◽  
Zhou Jingjun ◽  
Min Jingxin ◽  
Zhang Guang
Keyword(s):  
Numerical Simulations ◽  
Froude Number ◽  
Lift Coefficient ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Gravitational Effect ◽  
Gas Leakage ◽  
Supercavitating Vehicle ◽  
Numerical Predictions ◽  
Low Froude Number

A ventilated cavity was investigated using three-dimensional numerical simulation and cavitation water tunnel experiments under the condition of low Froude number. A two-fluid multiphase flow model was adopted in numerical predictions. The drag between the different phases and gravitational effect, as well as the compressibility of gas, was considered in the numerical simulations. By comparing the ventilated coefficient computational results of three different turbulence models with the Epshtein formula, the shear-stress-transport turbulence model was finally employed. The phenomenon of double-vortex tube gas-leakage was observed in both numerical simulations and experiments. Based on the validity of the numerical method, the change law of the lift coefficient on the afterbody was given by numerical predictions and accorded well with experimental results. The cause for the appearance of an abrupt increase in lift was difficult to get from experiments for the hard measurement, whereas the numerical simulations provided some supplements to analyze the reasons. The distribution of lift coefficient on the afterbody had important significance to the design of underwater vehicles.

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